36,110 research outputs found
Polymer Segmental Cross-Correlations from Dielectric Relaxation Spectra of Block Copolymers
Dielectric relaxation spectra of block polymers containing sequential type-A
dipoles are considered. Spectra of a specific set of block copolymers can be
combined to isolate the dynamic cross-correlation between the motions of two
distinct parts of the same polymer chain. Unlike past treatments of this
problem, no model is assumed for the underlying polymer dynamics.Comment: 7 pages, zero figure
Multicriteria decision making for enhanced perception-based multimedia communication
This paper proposes an approach that integrates technical concerns with user perceptual considerations for intelligent decision making in the construction of tailor-made multimedia communication protocols. Thus, the proposed approach, based on multicriteria decision making (MDM), incorporates not only classical networking considerations, but, indeed, user preferences as well. Furthermore, in keeping with the task-dependent nature consistently identified in multimedia scenarios, the suggested communication protocols also take into account the type of multimedia application that they are transporting. Lastly, this approach also opens the possibility for such protocols to dynamically adapt based on a changing operating environment and user's preferences
Intelligent synthesis mechanism for deriving streaming priorities of multimedia content
We address the problem of integrating user preferences with network quality of service parameters for the streaming of media content, and suggest protocol stack configurations that satisfy user and technical requirements to the best available degree. Our approach is able to handle inconsistencies between user and networking considerations, formulating the problem of construction of tailor-made protocols as a prioritization problem, solvable using fuzzy programming
Mass generation and the dynamical role of the Katoptron Group
Heavy mirror fermions along with a new strong gauge interaction capable of
breaking the electroweak gauge symmetry dynamically were recently introduced
under the name of katoptrons. Their main function is to provide a viable
alternative to the Standard-Model Higgs sector. In such a framework, ordinary
fermions acquire masses after the breaking of the strong katoptron group which
allows mixing with their katoptron partners. The purpose of this paper is to
study the elementary-scalars-free mechanism responsible for this breaking and
its implications for the fermion mass hierarchies.Comment: 15 LaTeX pages, some comments added, version published in Modern
Physics Letters
Phase mixing of a three dimensional magnetohydrodynamic pulse
Phase mixing of a three dimensional magnetohydrodynamic (MHD) pulse is studied in the compressive, three-dimensional (without an ignorable coordinate) regime. It is shown that the efficiency of decay of an Alfvénic part of a compressible MHD pulse is related linearly to the degree of localization of the pulse in the homogeneous transverse direction. In the developed stage of phase mixing (for large times), coupling to its compressive part does not alter the power-law decay of an Alfvénic part of a compressible MHD pulse. The same applies to the dependence upon the resistivity of the Alfvénic part of the pulse. All this implies that the dynamics of Alfvén waves can still be qualitatively understood in terms of the previous 2.5D models. Thus, the phase mixing remains a relevant paradigm for the coronal heating applications in the realistic 3D geometry and compressive plasma
Star-forming Galactic Contrails at z=3.2 as a Source of Metal Enrichment and Ionizing Radiation
A spectroscopically detected Lyman alpha emitting halo at redshift 3.216 in
the GOODS-N field is found to reside at the convergence of several Lyman alpha
filaments. HST images show that some of the filaments are inhabited by
galaxies. Several of the galaxies in the field have pronounced head-tail
structures, which are partly aligned with each other. The blue colors of most
tails suggest the presence of young stars, with the emission from at least one
of the galaxies apparently dominated by high equivalent width Lyman alpha.
Faint, more diffuse, and similarly elongated, apparently stellar features, can
be seen over an area with a linear extent of at least 90 kpc. The region within
several arcseconds of the brightest galaxy exhibits spatially extended emission
by HeII, NV and various lower ionization metal lines. The gas-dynamical
features present are strongly reminiscent of ram-pressure stripped galaxies,
including evidence for recent star formation in the stripped contrails. Spatial
gradients in the appearance of several galaxies may represent a stream of
galaxies passing from a colder to a hotter intergalactic medium. The stripping
of gas from the in-falling galaxies, in conjunction with the occurrence of star
formation and stellar feedback in the galactic contrails suggests a mechanism
for the metal enrichment of the high redshift intergalactic medium that does
not depend on long-range galactic winds, at the same time opening a path for
the escape of ionizing radiation from galaxies.Comment: 12 pages, 9 figures, submitted to MNRA
Age Related Changes in Cerebrovascular Reactivity and Its Relationship to Global Brain Structure
ACKNOWLEDGMENTS This study was funded by Alzheimerâs Research UK (ARUK) and the Aberdeen Biomedical Imaging Centre, University of Aberdeen. GDW, ADM and CS are part of the SINASPE collaboration (Scottish Imaging Network - A Platform for Scientific Excellence www.SINAPSE.ac.uk). The authors thank Gordon Buchan, Baljit Jagpal, Nichola Crouch, Beverly Maclennan and Katrina Klaasen for their help with running the experiment and Dawn Younie and Teresa Morris for their help with recruitment and scheduling. We also thank the residents of Aberdeen and Aberdeenshire, and further afield, for their generous participation.Peer reviewedPublisher PD
Nature of eclipsing pulsars
We present a model for pulsar radio eclipses in some binary systems, and test
this model for PSRs B1957+20 and J2051-0827. We suggest that in these binaries
the companion stars are degenerate dwarfs with strong surface magnetic fields.
The magnetospheres of these stars are permanently infused by the relativistic
particles of the pulsar wind. We argue that the radio waves emitted by the
pulsar split into the eigenmodes of the electron-positron plasma as they enter
the companion's magnetosphere and are then strongly damped due to cyclotron
resonance with the ambient plasma particles. Our model explains in a natural
way the anomalous duration and behavior of radio eclipses observed in such
systems. In particular, it provides stable, continuous, and frequency-dependent
eclipses, in agreement with the observations. We predict a significant
variation of linear polarization both at eclipse ingress and egress. In this
paper we also suggest several possible mechanisms of generation of the optical
and -ray emission observed from these binary systems.Comment: 12 pages, 5 figures, submitted to Ap
Penegakan Hukum Bagi Pelaku Pengeboman Ikan di Kabupaten Flores Timur
This research aims is to study about the law enforcement for fishermen who catch fishes with bomb in East Flores Regency. The research method uses empirical juridical. The data consist of primary and secondary data. Data are analysed by using qualitative analysis. The research results conclude that the law enforcement for fishermen who catch fishes with bomb in East Flores Regency are repressive, preventive and curative efforts. The most law enforcement is the repressive effort. The obstacles in this law enforcement are limited number of police personnel and the lack of facilities and infrastructure. Keywords : Law Enforcement, Fishermen, Bombs. Penelitian ini bertujuan untuk mengkaji penegakan hukum bagi pelaku yang menangkap ikan dengan menggunakan bom. Metode penelitian menggunakan yuridis empiris. Data yang digunakan dalam penelitian ini terdiri dari data primer dan data sekunder. Seluruh data dianalisis menggunakan analisis kualitatif. Hasil penelitian menyimpulkan bahwa penegakan hukum yang dilakukan oleh sub sistem Peradilan Pidana di Kabupaten Flores Timur meliputi upaya represif, preventif dan juga kuratif. Penegakan hukum yang paling banyak dalam bentuk upaya represif. Kendala kendala yang dihadapi dalam penegakan hukum ini meliputi jumlah personil kepolisian yang terbatas dan kurangnya sarana dan prasarana
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